1//===----------------------------------------------------------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8// UNSUPPORTED: c++03, c++11, c++14, c++17
9
10// <span>
11
12// template<class OtherElementType, size_t OtherExtent>
13// constexpr span(const span<OtherElementType, OtherExtent>& s) noexcept;
14//
15// Remarks: This constructor shall not participate in overload resolution unless:
16// Extent == dynamic_extent || Extent == OtherExtent is true, and
17// OtherElementType(*)[] is convertible to ElementType(*)[].
18
19#include <span>
20#include <cassert>
21#include <string>
22
23#include "test_macros.h"
24
25template <class T, std::size_t extent, size_t otherExtent>
26std::span<T, extent> createImplicitSpan(std::span<T, otherExtent> s) {
27 return {s}; // expected-error {{chosen constructor is explicit in copy-initialization}}
28}
29
30void checkCV() {
31 // std::span< int> sp;
32 std::span<const int> csp;
33 std::span< volatile int> vsp;
34 std::span<const volatile int> cvsp;
35
36 // std::span< int, 0> sp0;
37 std::span<const int, 0> csp0;
38 std::span< volatile int, 0> vsp0;
39 std::span<const volatile int, 0> cvsp0;
40
41 // Try to remove const and/or volatile (dynamic -> dynamic)
42 {
43 std::span< int> s1{csp}; // expected-error {{no matching constructor for initialization of 'std::span<int>'}}
44 std::span< int> s2{vsp}; // expected-error {{no matching constructor for initialization of 'std::span<int>'}}
45 std::span< int> s3{cvsp}; // expected-error {{no matching constructor for initialization of 'std::span<int>'}}
46
47 std::span<const int> s4{vsp};
48 // expected-error@-1 {{no matching constructor for initialization of 'std::span<const int>'}}
49 std::span<const int> s5{cvsp};
50 // expected-error@-1 {{no matching constructor for initialization of 'std::span<const int>'}}
51
52 std::span< volatile int> s6{csp};
53 // expected-error@-1 {{no matching constructor for initialization of 'std::span<volatile int>'}}
54 std::span< volatile int> s7{cvsp};
55 // expected-error@-1 {{no matching constructor for initialization of 'std::span<volatile int>'}}
56 }
57
58 // Try to remove const and/or volatile (static -> static)
59 {
60 std::span< int, 0> s1{csp0}; // expected-error {{no matching constructor for initialization of 'std::span<int, 0>'}}
61 std::span< int, 0> s2{vsp0}; // expected-error {{no matching constructor for initialization of 'std::span<int, 0>'}}
62 std::span< int, 0> s3{cvsp0};
63 // expected-error@-1 {{no matching constructor for initialization of 'std::span<int, 0>'}}
64
65 std::span<const int, 0> s4{vsp0};
66 // expected-error@-1 {{no matching constructor for initialization of 'std::span<const int, 0>'}}
67 std::span<const int, 0> s5{cvsp0};
68 // expected-error@-1 {{no matching constructor for initialization of 'std::span<const int, 0>'}}
69
70 std::span< volatile int, 0> s6{csp0};
71 // expected-error@-1 {{no matching constructor for initialization of 'std::span<volatile int, 0>'}}
72 std::span< volatile int, 0> s7{cvsp0};
73 // expected-error@-1 {{no matching constructor for initialization of 'std::span<volatile int, 0>'}}
74 }
75
76 // Try to remove const and/or volatile (static -> dynamic)
77 {
78 std::span< int> s1{csp0}; // expected-error {{no matching constructor for initialization of 'std::span<int>'}}
79 std::span< int> s2{vsp0}; // expected-error {{no matching constructor for initialization of 'std::span<int>'}}
80 std::span< int> s3{cvsp0}; // expected-error {{no matching constructor for initialization of 'std::span<int>'}}
81
82 std::span<const int> s4{vsp0};
83 // expected-error@-1 {{no matching constructor for initialization of 'std::span<const int>'}}
84 std::span<const int> s5{cvsp0};
85 // expected-error@-1 {{no matching constructor for initialization of 'std::span<const int>'}}
86
87 std::span< volatile int> s6{csp0};
88 // expected-error@-1 {{no matching constructor for initialization of 'std::span<volatile int>'}}
89 std::span< volatile int> s7{cvsp0};
90 // expected-error@-1 {{no matching constructor for initialization of 'std::span<volatile int>'}}
91 }
92
93 // Try to remove const and/or volatile (static -> static)
94 {
95 std::span< int, 0> s1{csp}; // expected-error {{no matching constructor for initialization of 'std::span<int, 0>'}}
96 std::span< int, 0> s2{vsp}; // expected-error {{no matching constructor for initialization of 'std::span<int, 0>'}}
97 std::span< int, 0> s3{cvsp}; // expected-error {{no matching constructor for initialization of 'std::span<int, 0>'}}
98
99 std::span<const int, 0> s4{vsp};
100 // expected-error@-1 {{no matching constructor for initialization of 'std::span<const int, 0>'}}
101 std::span<const int, 0> s5{cvsp};
102 // expected-error@-1 {{no matching constructor for initialization of 'std::span<const int, 0>'}}
103
104 std::span< volatile int, 0> s6{csp};
105 // expected-error@-1 {{no matching constructor for initialization of 'std::span<volatile int, 0>'}}
106 std::span< volatile int, 0> s7{cvsp};
107 // expected-error@-1 {{no matching constructor for initialization of 'std::span<volatile int, 0>'}}
108 }
109}
110
111int main(int, char**) {
112 std::span<int> sp;
113 std::span<int, 0> sp0;
114
115 std::span<float> s1{sp}; // expected-error {{no matching constructor for initialization of 'std::span<float>'}}
116 std::span<float> s2{sp0}; // expected-error {{no matching constructor for initialization of 'std::span<float>'}}
117 std::span<float, 0> s3{sp}; // expected-error {{no matching constructor for initialization of 'std::span<float, 0>'}}
118 std::span<float, 0> s4{sp0}; // expected-error {{no matching constructor for initialization of 'std::span<float, 0>'}}
119
120 checkCV();
121
122 // explicit constructor necessary
123 {
124 createImplicitSpan<int, 1>(sp);
125 }
126
127 return 0;
128}
129

source code of libcxx/test/std/containers/views/views.span/span.cons/span.verify.cpp